Drill collar



July 19, 1966 0 3,261,414

DRILL COLLAR Filed May 12, 1965 f/v/n 6. 50/66 INVENTOR.

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A r g/v5 VJ United States Patent r 3,261,414 DRILL COLLAR Elvin G. Boice, Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a corporation of Texas Filed May 12, 1965, Ser. No. 469,358 Claims. (Cl. 175-320) This invention relates generally to apparatus for drilling wells, and more particularly to a drill collar arrangement for connection to the lower end of a drill stem.

This application is a continuation-in-part application of my copending application Serial No. 194,237, filed May 14, 1962.

In the rotary drilling of deep wells, it is customary to employ heavy drill collars connected to the lower end of a lighter drill stem and to connect a drill bit to the lower end of the lowermost collar. The collars provide the necessary Weight for drilling, and, being on the lower end of the lighter and more flexible drill stem, the drill collars tend to make the drill bit drill straight.

It is an object of this invention to provide a new and improved drill collar particularly useful in the drilling of large boreholes.

Another object is to provide a new and improved drill collar arrangement to provide a large amount of weight concentrated close to the drill bit and to the bottom of the hole being drilled.

Other objects will become apparent from the following description and accompanying drawings in which:

FIGURE 1 is a side elevational view of the drill collar.

FIGURE 2 is a transverse sectional view taken along line 2-2 in FIGURE 1.

The drill collar of the invention is shown generally at 1, and comprises a central tubular member 2. The upper end of the tubular member 2 is threaded as at 3 for connection to the lower end of a drill stem (not shown). The lower end of the tubular member 2 is provided with an internally threaded box 4 for attachment to a drill bit (not shown). Near the lower end of the tubular member 2 is a lower flange member 5 which may have a plurality of threaded connectors-6 spaced radially from the member 2 and disposed circumferentially around the flange member 2. On the upper portion of the member 2 is provided an upper flange member 7 which has a plurality of holes 8 in axial alignment with the threaded connectors 6. Elongate satellite members 9, which may be rods or tubular members, are inserted through the holes 8 and threaded on to the threaded connectors 6.

The member 2 has a central-bore 10 to conduct drilling fluid, such as mud or compressed air, from the drill stem through the drill bit to wash the cuttings out of the borehole in the usual manner.

In the embodiment shown, three members 9 are spaced radially from and disposed around the central member 2, but it is obvious that more or less members 9 may be provided as desired depending upon the weight required for drilling the formations being encountered by the drill bit.

As shown, the three members 9 are of different lengths since it is contemplated that scrap drill collars may be used. Since the primary function of the members 9 is to provide weight to the device 1, the weight of each of the members 9 is comparable to the weight of the centnal tubular member 2. Any cylindrical or tubular member providing such weight, which will engage the threaded connectors 6 while extending through the holes 8 in the upper flange member 7, may be used as the mem- 3,261,414 Patented July 19, 1966 ice her 9 without departing from the present invention, including standard drill collars which are substantially the same as central tubular member 2.

This drill collar is particularly useful in the drilling of large boreholes, since a large amount of drilling weight is desired for drilling with a large bit, but the limited axial room available in a drilling rig may not afford the necessary distance required to supply the desired weight by connecting conventional drill collars end to end. In other words, a drilling rig may, for example, accommodate only three drill collars connected end to end, which three drill collars may not provide the drilling weight desired for drilling from the surface of the earth large boreholes on the order, for example, of 36 to 60 inches in diameter.

With my invention a cluster of three, six or more collars may be accommodated around a central member With the axial length of the drill collar arrangement being substantially that of only one collar.

This invention is not limited to the embodiment shown. Various changes within the scope of the following claims will occur to those skilled in the art.

What is claimed is:

1. A drill collar comprising,

a central tubular member,

a first flange on the lower portion of said central member,

a second flange on the upper portion of said central member,

the said first flange having a plurality of threaded connectors spaced radially from the said central member and disposed circumferentially therearound,

the said second flange member having a plurality of holes therethrough spaced radially from the said central member and aligned axially with said connectors, and

rigid elongate members adapted to be inserted through said holes and secured to said threaded connectors.

2. A drill collar comprising,

a central tubular member,

a first flange on the lower portion of said central member,

a second flange on the upper portion of said central member,

the said second flange member having a plurality of holes therethrough spaced radially from the said central member, and

rigid elongate cylindrical members adapted to be inserted through said holes and secured to said first flange,

each of said cylindrical members being of comparable weight to said member.

3. A drill collar comprising,

a central tubular member,

a plurality of elongate rigid members spaced radially from said central member and disposed circumferentially therearound, and

means to secure said elongate members to said central member,

each of said elongate members being of comparable weight to said central member.

4. A drill collar comprising,

a central tubular member,

two or more elongate rigid members spaced radially from said central member and disposed circumferentially therearound, and

3 means to secure said elongate members to said central member, each of said elongate members being of comparable Weight to said central member. 5. A drill collar comprising, a central tubular member,

a plurality of elongate members spaced radially from said central member, and

means to secure said elongate members to said central member,

each of said elongate members being of comparable Weight to said central member.

References Cited by the Examiner UNITED STATES PATENTS Wright 175-325 Betts 175-57 Van Every 166241 X Boice 175-320 Gehtke 175325 X Bruce 175320 10 CHARLES E. OCONNELL, Primary Examiner.

J. A. LEPPINK, Assistant Examiner. 

5. A DRILL COLLAR COMPRISING, A CENTRAL TUBULAR MEMBER, A PLURALITY OF ELONGATE MEMBERS SPACED RADIALLY FROM SAID CENTRAL MEMBER, AND MEANS TO SECURE SAID ELONGATE MEMBERS TO SAID CENTRAL MEMBER, EACH OF SAID ELONGATE MEMBERS BEING OF COMPARABLE WEIGHT TO SAID CENTRAL MEMBER. 